38 Trademarks applied for by Donald Trump were approved by China, after he was elected President. Spring Chang was Trump's Beijing-based lawyer for the transactions.

Emoluments Clause in the Constitution, just in case you can't quite recall it word for word:

From Article I, Section 9:  No Title of Nobility shall be granted by the United States: And no Person holding any Office of Profit or Trust under them, shall, without the Consent of the Congress, accept of any present, Emolument, Office, or Title, of any kind whatever, from any KIng, Prince, or foreign state.

I don't know where a Queen or Princess would fit in.

Don't worry: they'd be representative(s) of a foreign state.